Large-size metal-framed tower

ABSTRACT

A large size metal frame cooling tower of generally upright cylindrical configuration has an outer surface of metal frame work or panels. At least one stiffening ring is provided either on the inside or the outside of the cylindrical structure, or both. A crane may orbit the tower on one of the stiffening ring structures.

United States Patent 1 Marosi et al.

1 LARGE-SIZE METAL-FRAMED TOWER [75] Inventors: Istvan Marosi; FrigyesVolgyes, both of Budapest, Hungary Ipari Epulettervezo Vallalat,Budapest, Hungary Filed: Apr. 15,1971

Appl. No.: 134,368

Assignee:

Int. Cl E04g 11/04, BOlf 3/04 Field of Search 261/DIG. 11, 111; 212/57,64; 52/245, 246

References Cited UNITED STATES, PATENTS 10/1951 Pennington 52/245 8/1966Kalupin et a1. 52/245 US. Cl 261/111, 26l/DIG. 11, 212/57, I

Primary ExaminerTim R. Miles Assistant Examiner-Steven H. MarkowitzAttorney-Young & Thompson [57] ABSTRACT A large size metal frame coolingtower of generally upright cylindrical configuration has an outersurface of metal frame work or panelsuAt least one stiffening ring isprovided either on the inside or the outside of the cylindricalstructure, or both. A crane may orbit the tower on one of the stiffeningring structures.

5 Claims, 3 Drawing Figures LARGE-SIZE METAL-FRAMED TOWER The inventionrelates to large-size. metal-framed towers, especially to cooling towershaving a mantlesurface of circular cylinder-jacket shape.

According to the technical literature, cooling towers are built on thebasis of established design principles. One type of the knownconstruction of such character is the steelwork cooling tower the shapeof which may be cylindrical, frusto-conical type, prism of polygonalfloor plane, possibly some body of rotation, etc.

The above mentioned formations determine the suitable buildingtechnology but experience has shown that the construction of such towersalways requires the use of huge-size tower cranes of appropriateload-bearing capacity, being owing to the generally extraordinary heightof the construction different from the conventional. This, however, is adrawback since the production, transport and assembly of such especiallylarge-size tower cranes are expensive and complicated. Moreover, thebuilding of cooling towers at large distances and possibly at intervalsof several years does not render possible the rational and economicutilization of such huge tower cranes.

Considering now the statical development and force distribution of thetower constructions, owing to the great forces resulting in the firstplace from the wind load, large-size cooling towers are subject toconsiderable stresses and to deformations exceeding those usual inengineering practice. Therefore, such constructions can be designed onlyof profiles of large cross-section, with excessively high materialrequirements, that is, uneconomically. In addition, the constructionswith high material requirements need larger, more expensive and morecomplicated foundation works, resulting in further rise of theinvestment costs.

The invention aims at a structural design for largesize metal-framedtowers, especially cooling towers, having a mantle surface of circularcylinder-jacket shape which due to its configuration renders unnecessarythe useof expensive and unutilized tower cranes on the one hand, andprovides for a high rigidity as compared to conventional constructionson the other. Hence, tower construction can be realized with aconsiderably smaller material consumption, i.e. more economically, thanthe constructions known hitherto.

In accordance with this object, according to the invention, large-sizemetal-framed towers especially cooling towers with mantle surface ofcircular cylinderjacket shape are designed so that the mantle surface isdeveloped as a metal framework or made of panels, and along the mantlesurface outside and/or inside at least one stiffening ring participatingin the force distribution of the mantle surface and at the same timeserving as an auxiliary assembly element is arranged.

A further characteristic of the construction according to the inventionconsists in that the mantle of the tower can be a cylinder or body ofrotation of optional directrix and of straight, polygonal or optionallycurved generatrix.

The stiffening rings are preferably ring or discshaped planar girders ofhigh rigidity, the plane of which is perpendicular to the generatrix ofthe mantle surface.

In another solution, the stiffening rings may be ringor disc-shapedgirders, the plane of which encloses an angle with the generatrix of themantle surface.

The stiffening rings are provided with a positive guide for thecircumvolution of a crane mechanism and lift ing means for moving thestiffening rings are fastened to the mantle surface of the tower,preferably to its current highest level. i

The large-size metal-framed towers according to the invention haveseveraladvantageous properties in comparison to the constructions ofsimilar purpose known hitherto. One of the most important thereof isthat the proposed construction combines the advantages of spatiallattice girders and shell structures. This means that the forcedistribution of the tower according to the invention is similar to thatof the shell structure, consequently it is highly economical as tomaterial requirement and at the same time, of the same rigidity as thespatial lattice girders.

Another design factor should also be mentioned here, namely that withthe shell structures the secondary effects i.e. that the deformationsoccurring under the effect of loads react on the force distribution ofthe structure are usually not taken into consideration owing to theircomplexity (that is, they are taken into consideration only when using acomputer). These so-called secondary effects, however, can be veryconsiderable. In the case of the construction proposed by the invention,on the contrary, these secondary effects are very low, and arenegligible. The main reason therefor is that the stiffening ringsparticipate in the force distribution of the mantle surface.

The comparative examinations carried out from the point of view of thematerial consumption show that in case of for instance a cone-mantleshaped tower the steel used according to the invention amounts to onlyabout 50 per cent of the conventional amount and the static stressesoccurring in the foundation are only about one-eighth of those occurringwith constructions without stiffening rings. Similar comparisons weremade in the case of a tower designed with a hyperbolic mantle surfaceand a similarly considerable material saving of about 30 per cent wasobserved in favour of the construction proposed by the invention.

The invention is explained by means of the accompanying drawing by wayof examples, where FIG. 1 shows the half longitudinal section of thelarge-size metal-framed tower according to the invention,

FIG. 2 is the half side-view of the tower mantle,

FIG. 3 indicates the longitudinal section of the tower constructionshown so that in the left side of the drawing a horizontal section takenin the plane of the inner stiffening ring is represented, whereas in theright side of the drawing that taken in the plane of the ground level isshown.

In FIG. 1 the mantle l of the tower construction is schematically shownwhich is in the given case composed of panels but may be constructedalso of lattice girders. On the inside of the mantle surface 1 there isthe inner stifiening ring 2, and on its outer side, the outer stiffeningring 3. Such stiffening rings may be ap' plied along the mantle surfaceof the tower in optional number, arrangement and division. Thestiffening rings may be located alternately at the inside and outside,and it is possible, too, to provide either exclusively outer stiffeningrings or exclusively inner ones and there is no objection at all tomaking the inner and outer stiffening rings in irregular succession.

These stiffening rings participate in the force distribution of themantle surface when the construction is properly used, and play alreadyan important part during the mounting operation. The use of thesestiffening rings renders possible the building of the completeconstruction without any tower crane. The stifiening rings areexpediently developed as lattice girders of horizontal plane, providedwith a positive guide 4 which permits the movement of some light andsimple erecting crane.

By means of the said erecting crane not shown in the drawing the panelelements 5 may be lifted from the ground and located in the followinglevel of the mantle surface of the tower. The complete new level made ofpanel elements 5 being finished, the stiffening ring may be lifted tothe uppermost level by means of some appropriate lifting device, forinstance of winch and hoist, or of hydraulic lifting system.

The tower construction can be made of commercially used mild steel, ofhigh-tensile steel or of suitably chosen aluminum alloy. The elements ofthe construction can be developed not only of panel elements 5 butasshown in FIG. 2 as simple metal frameworks 6. The structural elementscan be interconnected by any structural joint known by itself.

What We claim is:

l. A large size metal frame cooling tower in the form of a hollowupright cylinder of metal framework, at least one stiffening ringconcentric with the tower, and a plurality of structural elementsextending from the stiffening ring diagonally downwardly and connectedto the tower at a level lower than the stiffening ring, the space alongthe tower above and below at least one said ring being free said ringhaving a horizontal guide on its upper surface for an erecting crane.

2. A tower as claimed in claim 1, and structural elements extendingdiagonally upwardly from the stifiening ring and secured to the tower. I

3. A cooling tower as claimed in claim 1, there being a plurality ofsaid rings vertically spaced apart along the height of the tower.

4. A tower as claimed in claim 3, one of said rings being disposedinside the tower and another of said rings being disposed outside thetower.

5. A tower as claimed in claim 4, said another ring being disposed lowerthan said one ring, and structural framework extending diagonallyoutwardly and downwardly from said another ring into supportingengagement with the ground at a distance outside the lower end of saidtower.

1. A large size metal frame cooling tower in the form of a hollowupright cylinder of metal framework, at least one stiffening ringconcentric with the tower, and a plurality of structural elementsextending from the stiffening ring diagonally downwardly and connectedto the tower at a level lower than the stiffening ring, the space alongthe tower above and below at least one said ring being free said ringhaving a horizontal guide on its upper surface for an erecting crane. 2.A tower as claimed in claim 1, and structural elements extendingdiagonally upwardly from the stiffening ring and secured to the tower.3. A cooling tower as claimed in claim 1, there being a plurality ofsaid rings vertically spaced apart along the height of the tower.
 4. Atower as claimed in claim 3, one of said rings being disposed inside thetower and another of said rings being disposed outside the tower.
 5. Atower as claimed in claim 4, said another ring being disposed lower thansaid one ring, and structural framework extending diagonally outwardlyand downwardly from said another ring into supporting engagement withthe ground at a distance outside the lower end of said tower.